OPEFB pretreatment using the low-cost N,N,N-dimethylbutylammonium hydrogen sulfate ionic liquid under varying conditions

S M Shahrul Nizan Shikh Zahari; Yichen Liu; Putian Yao; Mahfuzah Samirah Ideris; Hazeeq Hazwan Azman; Jason P Hallett

doi:10.1038/s41598-023-48722-0

OPEFB pretreatment using the low-cost N,N,N-dimethylbutylammonium hydrogen sulfate ionic liquid under varying conditions

Sci Rep. 2023 Dec 15;13(1):22354. doi: 10.1038/s41598-023-48722-0.

Authors

S M Shahrul Nizan Shikh Zahari^#^{1

2}, Yichen Liu^#^{3

4}, Putian Yao³, Mahfuzah Samirah Ideris⁵, Hazeeq Hazwan Azman⁶, Jason P Hallett⁷

Affiliations

¹ Department of Chemical Engineering, Faculty of Engineering, South Kensington Campus, Imperial College London, London, SW72AZ, UK. shahrul.zahari@usim.edu.my.
² Industrial Chemical Technology Programme, Faculty of Science and Technology, Universiti Sains Islam Malaysia, Bandar Baru Nilai, 71800, Nilai, Negeri Sembilan, Malaysia. shahrul.zahari@usim.edu.my.
³ Department of Chemical Engineering, Faculty of Engineering, South Kensington Campus, Imperial College London, London, SW72AZ, UK.
⁴ Key Laboratory of Green Chemistry and Technology, Ministry of Education, College of Chemistry, Sichuan University, 29 Wangjiang Road, Chengdu, 610064, Sichuan, People's Republic of China.
⁵ Industrial Chemical Technology Programme, Faculty of Science and Technology, Universiti Sains Islam Malaysia, Bandar Baru Nilai, 71800, Nilai, Negeri Sembilan, Malaysia.
⁶ Centre for Foundation and General Studies, Universiti Selangor, Jalan Timur Tambahan, 45600, Bestari Jaya, Selangor Darul Ehsan, Malaysia.
⁷ Department of Chemical Engineering, Faculty of Engineering, South Kensington Campus, Imperial College London, London, SW72AZ, UK. j.hallett@imperial.ac.uk.

^# Contributed equally.

Abstract

This study investigates the effects of temperature and period on the pretreatment of OPEFB using the low-cost N,N,N-dimethylbutylammonium hydrogen sulfate ionic liquid ([DMBA][HSO₄] IL) with 20 wt% of water. The results demonstrate that higher pretreatment temperatures (120, 150, and 170 °C) and longer periods (0.5, 1, and 2 h) enhanced lignin recovery, resulting in increased purity of the recovered pulp and subsequently enhanced glucose released during enzymatic hydrolysis. However, at 170 °C, prolonging the period led to cellulose degradation and the formation of pseudo-lignin deposited on the pulps, resulting in a decreasing-trend in glucose released. Finally, the analysis of extracted lignin reveals that increasing pretreatment severity intensified lignin depolymerisation and condensation, leading to a decrease in number average molecular weight (M_n), weight average molecular weight (M_w) and polydispersity index (Đ) values.

Grants and funding

RACER/1/2019/TK05/USIM//1/ID.17091/Ministry of Higher Education, Malaysia